Riveting apparatus

ABSTRACT

Riveting apparatus which, when actuated, automatically performs a cycle of operations including supplying a tubular rivet to a setting station and setting the rivet, is of the kind comprising an elongate mandrel having an enlarged head at its forward end, and pulling jaws for holding and pulling the mandrel rearwardly to draw the enlarged head through the rivet bore and set the rivet. Rivets are fed forwardly along the mandrel from the rear end and the pulling jaws are mounted for opening and closing movement to allow rivets to pass. The pulling jaws are movable in the lengthwise direction of the mandrel in both their open and closed condition and serve to pull the mandrel rearwardly to set a rivet, to return the mandrel forwardly and to advance rivets along the mandrel to the setting station. An air jet advances rivets forwardly past the pulling jaws and a detent holds the mandrel when the pulling jaws are open. The apparatus is operated pneumatically under the control of a logic circuit.

United States Patent Sheffield et al.

[ Aug. 13, 1974 RIVETING APPARATUS Assignee: Aerpat A.G., Zug,Switzerland Filed: May 26, 1972 Appl. No.: 257,200

U.S. Cl. 72/391 Int. Cl B21j 15/18 Field of Search 72/391, 424, 453;227/55;

References Cited UNITED STATES PATENTS l/l944 Lee 72/391 l/l97l Heslop72/39l 2/l973 Prosser 72/39l Primary ExaminerCharles W. Lanham AssistantExaminer-Gene P. Crosby Attorney, Agent, or FirmOblon, Fisher, Spivak,McClelland & Maier [57} ABSTRACT Riveting apparatus which, whenactuated, automatically performs a cycle of operations includingsupplying a tubular rivet to a setting station and setting the rivet, isof the kind comprising an elongate mandrel having an enlarged head atits forward end, and pulling jaws for holding and pulling the mandrelrear wardly to draw the enlarged head through the rivet bore and set therivet. Rivets are fed forwardly along the mandrel from the rear end andthe pulling jaws are mounted for opening and closing movement to allowrivets to pass. The pulling jaws are movable in the lengthwise directionof the mandrel in both their open and closed condition and serve to pullthe mandrel rearwardly to set a rivet, to return the mandrel forwardlyand to advance rivets along the mandrel to the setting station. An airjet advances rivets forwardly past the pulling jaws and a detent holdsthe mandrel when the pulling jaws are open. The apparatus is operatedpneumatically under the control of a logic circuit.

32 Claims, 14 Drawing Figures PATENTED nus] 31974 SHEET 8 ur a RIVETINGAPPARATUS This invention relates to blind riveting apparatus for settingblind tubular rivets of the kind comprising a shank and an enlarged headat one end of the shank, and having a bore extending through the headand shank. Such rivets are well known and are commercially availableunder the registered Trade Mark Chobert.

More particularly the invention relates to blind riveting apparatuswhich is adapted to supply blind tubular rivets to a setting station,and to set the rivets at the setting station.

According to the invention there is provided blind riveting apparatuscomprising abutment means for supporting a rivet in a rivet settingoperation,

an elongated mandrel having an enlarged head and a stem extendingrearwardly of the head, the mandrel being movable lengthwise of itsaxis, relative to the abutment means, to pull the enlarged head througha tubular rivet supported by the abutment means,

first and second holding means each of which may be in or out ofengagement with the mandrel and each of which is arranged to hold themandrel at a time when the other of the holding means is out ofengagement with the mandrel,

the first holding means being reciprocable in the axial direction of themandrel between a forward and a rearward location, and movable in adirection transverse to the mandrel axis between a mandrelholdingposition and a position remote from the mandrel and through a rivetfeeding position between said mandrel-holding position and said remoteposition, the first holding means being operable to hold and to move themandrel lengthwise of its axis whilemoving between the said forwardlocation and an intermediate location between the forward location andthe rearward location, and in the rivet feeding position, to engage arivet on the mandrel stem while moving independently of the mandrelbetween the said intermediate location and the rearward location, and,in the remote position at the rearward location to allow a rivet to movealong the mandrel past the first holding means,

means being provided for advancing rivets forwardly along the mandrelfrom the rearward end thereof and past the first holding means.

The first holding means may comprise a pair of pulling jaws.

Each pulling jaw may be associated with a cam which I constrains the jawto move between the mandrelholding position and the said position remotefrom the mandrel.

Each pulling jaw may be spring biassed to move transversely towards theposition remote from the mandrel and may be constrained to move inopposition to the spring bias by the associated cam.

The second holding means may be disposed rearwardly of the holding.means.

The means for advancing rivets forwardly from the rear end of themandrel and past the first holding means may comprise jet means fordirecting a jet of gas forwardly along the mandrel.

The jet means may be disposed rearwardly of the rear end of themandrelwhen the mandrel is in its rearward position.

A preferred embodiment of the invention will now be described by way ofexample with reference to the accompanying diagrammatic drawings, inwhich:

FIGS. 1 to 4 are schematic views from the front of a blind rivetingmachine showing the positions of parts of the machine in successivestages of operation;

FIG. 5 is a schematic side view corresponding to FIG.

FIG. 6 is a schematic side view showing parts of the machine in afurther stage of operation;

FIG. 7 is sectional elevation through part of the machine taken on theline VII-VII of FIG. 13 and corresponding generally to the views shownin FIGS. 1-4;

FIG. 8 is a sectional elevation through part of the machine taken on theline VIII-VIII of FIG. 12 and corresponding generally to the views shownin FIGS. 5 and FIG. 9 is a section on the line IX-IX of FIG. 8;

FIG. 10 is a side elevation of a mandrel forming part of the machine;

FIG. II is a schematic diagram illustrating a pneumatic circuit forcontrolling operation of the machine;

FIG. 12 is a front elevation of the complete machine;

FIG. 13 is a side elevation of the complete machine;

FIG. 14 is a section on the line XIV-XIV of FIG. 8.

The riveting machine of this embodiment is intended for setting blindtubular rivets of the kind comprising a shank and an enlarged head atone end of the shank, and having a bore extending through the head andshank. Such rivets are well known and are commercially available underthe registered Trademark Chobert." Such rivets are set by means of amandrel having a stem on which the rivets are a sliding fit, and anenlarged head at one end of the stem, each rivet being threaded onto themandrel stem with the tail end of the rivet (i.e., the end of the rivetshank remote from the rivet head) towards the head of the mandrel, andthe mandrel is then pulled to draw the mandrel head through the rivetbore, thereby expanding the shank of the rivet. A plurality of rivetsmay be loaded onto the stem of the mandrel with their tail ends towardsthe mandrel head, and can then be set by pulling the mandrel to draw thehead through the rivets successively.

The machine of this embodiment is adapted to automatically maintain asupply of rivets to a rivet setting station and to set the rivets in asuitable apertured workpiece at the setting station from below theworkpiece. Thus, rivets are presented at the setting station head downand tail extending vertically upwards, the workpiece being positioned sothat the tail of the rivet projects through an aperture in theworkpiece, and the rivet is then set. A further rivet is thenautomatically presented at the setting station ready for setting.

The riveting machine comprises a riveting head together with means forstoring and supplying rivets to the riveting head, and control gear forcontrolling the operation of the riveting head.

The construction of the riveting head is shown in detail in FIGS. 7 and8 but some of its more important parts are illustrated schematically inFIGS. 1 to 6 in which the relationships of these parts in differentstages of operation of the machine can readily be seen.

The riveting head 10 comprises a mandrel 12 having an elongated stem 14and a head 16 at one end of the stem. The head end of the mandrel isregarded as the forward end, the other end being the rear end of themandrel. The mandrel is reciprocable along its axis in relation to apair of nose-jaws 18, 20 which are arranged on opposite sides of themandrel stem at a position adjacent to the head. The nose-jaws eachpresent a forwardly facing abutment surface 22, 24 adjacent to themandrel and are resiliently urged towards a closed position in whichthese abutment surfaces normally cooperate to form an annular abutmentperipherally of the mandrel. When the mandrel is moved forwardly, thehead is spaced forwardly of the nose-jaws, (i.e., above them in thenormal attitude of the riveting head) as shown in FIG. 5, and when themandrel is moved to its rearward position, the head is disposed betweenthe jaws so that the forward end of the mandrel is flush with or evenbehind the abutment surfaces of the nose-jaws.

The mandrel is reciprocated by means of a pair of pulling jaws 26, 28situated rearwardly of the nosejaws. The pulling jaws are movablebetween a closed position in which they cooperate to hold the mandreland an open position in which they are disengaged from the mandrel, andare also reciprocable in the lengthwise direction of the mandrel. Themovements of the pulling jaws are rather complex and will be discussedhereinafter: suffice it to say here that, when the mandrel is in itsrearward position, the pulling jaws disengage from the mandrel and so donot hold it in the rearward position. However, when the mandrel is atits rearward position it is engaged and held by a detent 30 situatedrearwardly of the pulling jaws. The detent 30 comprises a ball 32 whichis urged by a compression spring 34 to engage in a peripheral groove 36formed in the mandrel stem near the rear end of the mandrel.

A pair of rivet locating jaws 38, 40 are disposed on opposite sides ofthe mandrel axis at a position immediately forward of the detent butgenerally rearwardly of the rear end of the mandrel when the mandrel isin its forward position. The locating jaws are able to open and close insynchronism with the opening and closing of the pulling jaws.

A rivet locating plunger 58, shown schematically in FIGS. and 6, isreciprocable at right angles to the mandrel axis to deliver rivets oneat a time from the rivet supply means into position between the closedcating jaws when the mandrel is in its forward position. A rivet thusdelivered is held rearwardly of the mandrel by the locating jaws withits bore aligned with the mandrel and with the tail end of the rivettowards the noseaws.

A jet 42 is arranged on the axis of the mandrel at a position which isto the rear of the rear end of the mandrel when the mandrel is in itsrearward position, and is arranged to direct a stream of air or othergas forwardly along the mandrel. The jet is connected through conduit(not shown) to a source of pressurized air or other gas.

A feature which enables the riveting head to operate upwardly (i.e.,from below a workpiece as distinct from downwardly with the rivetinghead above the workpiece or horizontally with the riveting head to oneside of a workpiece) is the provision of a latch 44 which is resilientlyurged into a position close to or engaging the mandrel and which movespivotally away from the mandrel to allow rivets to move forwardly alongthe mandrel past the latch but prevents the rivets from movingrearwardly past the latch under the influence of gravity.

The sequence of operation of the parts so far referred to is as follows:

Referring first to FIG. 1, in which the mandrel 12 is in its forwardposition relative to the nose-jaw 18, and the pulling jaws 26, 28 are intheir forward position and gripping the stem 14 of the mandrel andthereby holding the mandrel, it will be seen that the mandrel stem 14extends through four rivets of which three rivcts, indicated by thereference numerals 46, 48, 50, form a column generally to the rear ofthe nose-jaws and are supported by the pulling jaws 26, 28. The fourth,or leading rivet 52 has passed forwardly of the nose-jaws, 18, 20 and issupported against rearward movement by the abutment surfaces 22, 24 ofthe nose- 20 jaws.

It will be noted also that another rivet, referred to as a fed rivet 54,is located between the locating jaws 38, 40 which are in their closedcondition and that the rear end of the mandrel is forward of the fedrivet and aligned with the bore of the fed rivet.

In practice, and as shown in FIGS. 7 and 8, the distance between thepulling jaws, when in their forward position, and the nose jaws isgreater than the length of a column of three rivets, and consequentlythe number of rivets forming the column is appropriate to the actualdistance between the pulling jaws and nose-jaws.

In the condition shown in FIG. 1, the riveting head is ready to set theleading rivet 52, and in use, a suitably apertured workpiece (not shown)is now brought into position, the head of the mandrel being passedthrough the aperture in the workpiece and the workpiece is lowered untilits lower surface abuts the head of the leading rivet 52 and the shankof the leading rivet extends through the aperture of the workpiece. Theriveting head is then actuated to set the rivet.

Actuation of the riveting head causes it to perform automatically acycle of operations which is completed by the return of the rivetinghead to the condition shown in FIG. 1.

On actuating the riveting head, the pulling jaws 26, 28 move rearwardlywhile still gripping the mandrel, pulling the mandrel rearwardly untilthe mandrel head has passed right through the bore of the leading rivet52 and the forward end of the mandrel has come to lie flush with theabutment surfaces of the nose-jaws. As previously indicated, the passageof the mandrel head through the leading rivet sets the rivet, causingthe rivet to firmly engage the workpiece, and disengages the mandrelfrom the leading rivet.

Simultaneously with the setting of the leading rivet, the rearwardmovement of the mandrel has caused the rearward end of the stem of themandrel to pass through the bore of the fed rivet 54 so that the fedrivet is now threaded on the mandrel stern, and the ball 32 of thedetent 30 has engaged in the peripheral groove 36 near the rearward endof the mandrel, the detent spring 34 having yielded previously to allowthe portion of the stem between the groove and the rear end of themandrel to pass the detent.

As the pulling jaws move rearwardly, pulling the mandrel, the column ofrivets supported by the pulling jaws also moves rearwardly under theinfluence of gravity until the rearmost rivet 50 of the column abuts thelatch 44. The latch prevents further rearward movement of the column ofrivets so that they do not follow the further rearward movement of thepulling jaws.

With the mandrel now in its rearmost position, in which it is held bythe engagement of the detent ball 32 in the peripheral groove of themandrel stern, and with the column of rivets 46, 48, 50 supportedagainst further rearward movement by the latch, the pulling jaws nowbegin progressively to open while continuing to move rearwardly andsimultaneously the locating jaws 38, 40 also begin to open. This stageis shown in FIG. 2

The rearward and opening movements of the pulling jaws continue untilthe pulling jaws reach their rearmost position in which they are fullyopen and the eating jaws are also fully opened.

A stream of air or other gas is then delivered through the jet and, onengaging the head of the fed rivet 54, drives the fed rivet forwardlypast the pulling jaws until it abuts the rearward side of the latch asshown in FIG. 3. The stream of air is sustained to maintain the fedrivet in abutment with the latch and the pulling jaws now begin to moveforwardly and to close progressively. On reaching the head of the fedrivet 54, the pulling jaws are closed sufficiently to abut the fed rivetbut not to grip the mandrel. The pulling jaws continue to move forwardlywithout .gripping the mandrel and in doing so urge the fed rivet 54forwardly past the latch which yields resiliently to permit the rivetand jaws to pass. This stage of operation is shown in FIGS. 4 and 5.Thus, when the fed rivet is advanced along the mandrel, it strikes thelatch and causes deflection of the latch. However, the pulling jaws areso shaped that they also will deflect the latch when moving eitherforwardly or rearwardly pastthe latch.

The pulling jaws continue to move forwardly and eventually close uponand grip the mandrel stem at the same position as before, having urgedthe rivets 46, 48, 50 forward along the mandrel stem by a distance equalto the length of the fed rivet. The closed pulling jaws continue toadvance, now carrying forwardly the mandrel, the rivets 46, 48, 50 andthe fed rivet 54.

As the pulling jaws move forwardly past the latch 44 they becomedisengaged from the latch which returns resiliently to the positionclose to the mandrel stem. At this stage the rivet locating plunger 58is actuated to deliver a further rivet 56 from the rivet supply meansinto position between the closed locating jaws and cuts off the supplyof air to the jet 42. The further rivet 56 thus comes eventually tooccupy the position formerly occupied by the fed rivet 54 at thebeginning of the cycle, and remains there to constitute a fed rivet inthe next cycle.

As the pulling jaws continue to move forwardly, the rivet 46 comes intoabutment'with the resilient nosejaws and urges the nose-jaws to open.This stage is shown in FIG. 6, from which it will be appreciated thatthe pulling jaws have not quite reached the forward end of their strokeand the locating plunger 58 is still in the course of delivering thefurther rivet 56 towards the 10- cating jaws.

As the pulling jaws complete their forward movement, they advance therivet 46 through the opened nose-jaws and the nose-jaws then resilientlyclose behind the rivet 46 to provide an annular abutment rearwardly ofthe head of the rivet 46 which thus assumes the position formerlyoccupied by the leading rivet 52. Having advanced the rivet 46 to theposition of the leading rivet, the pulling jaws and mandrel reach theend of their forward stroke and stop. By this time, the delivery of thefurther rivet 56 into position between the locating jaws is alsocomplete and the riveting head is again in the condition shown in FIG. 1and ready to commence a further cycle.

Further details of the construction of the machine will now be describedwith reference to FIGS. 7 to 14.

In FIGS. 7 and 8, the condition of the machine is the same as shown inFIG. 1, the pullingjaws 26, 28 being in their fully forward position andgripping the mandrel 12.

The riveting head 10 comprises a rectangular frame 60 having horizontal,parallel upper and lower cross members 62, 64 respectively which areheld in spaced relation by right and left vertical members 66, 68respectively. A rail 70 extends horizontally between the verticalmembers at a position approximately midway between the upper and lowercross members.

A vertical plate 72 is secured to the lower cross member 64 and theupper cross member 62 and supports means for storing and supplyingrivets to the riveting head.

The means for storing and supplying rivets comprises a side blade hopperfeeder 74 of conventional construction and a flight 76. The side bladehopper feeder is arranged to contain a supply of tubular rivets andorientates and delivers the rivets to the flight in side by siderelationship with their heads uppermost and their shanks depending fromthe rivet-heads. The flight provides a surface 78 which is downwardlyinclined at an angle of about 30 and formed with a longitudinal slot 80down which the rivets slide under the influence of gravity, the rivetheads being supported by the surface 78 and the rivet shanks dependinginto the slot 80. Towards the lower end of the flight, the surface 78curves downwardly through an angle of about I50". A curved plate 82serves to support the rivets with their shanks in the groove as theypass down the curved portion of the flight and thereby become invertedwith their heads lowermost and supported by the plate, and their shanksupstanding in the groove.

A double acting pneumatic jack 84 for moving the pulling jaws 26, 28 ismounted on the lower cross member 64. The jack comprises a pneumaticcylinder 86, a piston 88 and a piston rod 90. The cylinder 86 is boltedto the underside of the lower cross member with its axis vertical. Thepiston rod 90 is axially aligned with the cylinder and extends upwardlythrough an annular seal 92 mounted in a central hole in the lower crossmember. The lowerend of the piston rod is secured to the piston 88 whichsweeps the bore of the cylinder and the pulling jaws 26, 28 arepivotally attached to the piston rod which is bifurcated at its upperend. Upper and lower ports (not shown) are provided adjacent the upperand lower ends respectively of the cylinder. Admission of air throughthe lower port drives the piston upwardly, raising the piston rod, andadmission of compressed air through the upper port drives the pistondownwardly, lowering the piston rod.

The pulling jaws 26, 28 are identical, and each comprises a verticallimb 94, 95 integral at its upper end with a cylindrical housing 96 andat its lower end with an arm 98.

The vertical limbs of the two pulling jaws 26, 28 extend throughelongate openings 100, 102 in the rail, so that the arms are below therail and the housings are above the rail. The arm of each pulling jawextends at right angles to the vertical limb and the housing extendsacross the other end of the limb and parallel to the arm. The free endportion of the arm of each jaw 26, 28 is offset to provide a singletongue 104. The tongues of the two jaws are each formed with an aperturethrough which passes a pivot pin 106 by which both the pulling jaws arepivotally attached to the bifurcated upper end of the piston rod, theoffset arrangement of the tongues of the arms of the two pulling jawsallowing both pulling jaws to be mounted on the same pivot pin while thevertical limbs and housings lie in a single plane. The

vertical limbs'94, 95 are each formed with a longitudinal guide face108, 110 respectively. The housings of the two pulling jaws are alignedwith each other and their adjacent ends are externally tapered at 112.Each housing has a stepped horizontal bore which has a wide portion 114at the outer end of the housing and which is stepped at 120 to a narrowbore portion 122 which extends through the tapered portion 112 of thehousing to that end of the housing which is adjacent to the other jaw.Disposed within the housing of each jaw is a mandrel gripping member 116and a pressure exerting member 124. The pressure exerting member 124 comprises a cylindrical block 126 which is slidable-within the wide boreportion 114 of the housing, and a stem 128 which extends from the blockinto the narrow bore portion 122. The mandrel gripping member 116comprises a cylindrical block 118 and three hardened steel fingers, 130,132 and 134 projecting from the tapered portion 112 of the housing, twoof the fingers, 130 and 132, being spaced apart and vertically alignedon one side of the mandrel axis and the other finger 134 being offset totheother side ofthe mandrel axis and between the other two fingers, thefingers of each jaw interdigitating with the fingers of the other jawand cooperating to grip the mandrel when the jaws are in their closedposition. A plurality of belleville washers 136 are shown disposedbetween the block 124 and the step of each jaw. The purpose of thesewashers is merely to facilitate accurate adjustment of the grippingmembers, 116 to enable the fingers to suitably grip the mandrel.

Mounted at the outer end of each of the housings is a cam followerroller. Each of the cam follower rollers 140, 141 is mounted on a shaft142, 143 respectively for rotation about a horizontal axis transverse tothe bore of its jaw housing. Two cam blocks 144, 146 are secured at theinwardly facing sides of the right and left vertical membersrespectivelyof the frame by pairs of tension bolts 148, 150 (only oneboltof each pair being shown in FIG. 7) which pass through each of thevertical members into threaded engagement with the cam blocks. Pairedupper and lower spacing bolts 152, 154 (of which only one of each pairis shown) extend through each of the vertical members in threadedengagement therewith into abutment with the outwardly facing surface ofthe cam block secured thereto. By suitable adjustment of the tensionbolts and space bolts, the distance between the inwardly facing surfaces156, 158 of the two cam blocks can be adjusted. The inwardly facingsurfaces of the two cam blocks 144, 146

constitute opposing cam surfaces against which the cam follower rollersof the pulling jaws run. Tension springs, 160, 162 are secured at one oftheir ends to the lower ends of the cam'blocks by means of pins 164, 166and their other ends are attached to pins 168, 170 which are slidableagainst the guide faces 108, 110 of the vertical limbs of the pullingjaws. The tension springs urge the pulling jaws to pivot outwardly so asto maintain the cam follower rollers in abutment with the cam surfaces156, 158 of the cam blocks.

The inwardly facing cam surfaces 156, 158 of the cam blocks each providethree distinct cam faces, namely a forward cam face 172, an intermediatecam face 174, and a rearward cam face 176. The forward and rearward camfaces of the two cam blocks are parallel to each other, and asillustrated in FIG. 7, the rearward cam faces of the two cam-blocks 144,146 are spaced apart by a distance greater than the distance between theforward cam faces of the two blocks. The intermediate cam face on eachblock is inclined between the forward and rearward cam faces and thedistance between the intermediate faces of the two cam blocksdecreasesprogressively in the upward or forward directron.

With the pulling jaws 26, 28 in their raised or forward position asshown in FIG. 7, the cam follower rollers 140, 141 abut the forward camfaces 172 of the cam blocks which are so adjusted that the pulling jawsare held in their fully closed position with the steel fingers of themandrel-gripping means of the two pulling jaws interdigitating to gripthe mandrel between them.

Actuation of the jack 84 to lower the piston rod and move the pullingjaws downwardly or rearwardly, causes the cam follower rollers totraverse the cam faces of the cam blocks in the rearward direction.While the cam follower rollers are traversing the forward cam faces ofthe cam blocks, the jaws are held in their closed position. When the camfollower rollers traverse the intermediate cam faces of the cam blocksin the rearward direction, they are constrained to follow the profile ofthe cam block by urging of the tension springs and accordingly, thepulling jaws progressively open as they move rearwardly. When the camfollower rollers reach the rearward cam face of the cam blocks they arein the fully open position and further rearward movement of the pullingjaws with the cam follower rollers traversing the rearward cam facesdoes not cause them to open to any greater degree. Conversely, when thejack is actuated to raise the pulling jaws, the cam follower rollersinitialy traverse the rearward cam faces of the cam blocks so that thepulling jaws move forwardly in their fully open position until the camfollower rollers encounter the intermediate cam faces of the cam blocks.Thereupon, continued forward movement of the pulling jaws is accompaniedby progressive closing of the pulling jaws and finally, when the camfollower rollers reach the forward cam faces of the cam blocks, thepulling jaws move forwardly without further closing.

The upper cross member 62 has a central aperture 178 in which is mountedthe lower end of a vertical tube 180. At the upper end of the tube ismounted a nosepiece 182.

The nosepiece 182 comprises a tubular body 184, the nose-jaws, 18, 20and a helical compression spring 186. The tubular body 184 is screwed tothe upper end of the vertical tube 180. The nose-jaws are of generallysemi-cylindrical shape, and cooperate with each other to formsubstantially a tube peripherally of the mandrel 12. The compressionspring 186 abuts an inwardly projecting flange 188 at the forward end ofthe tubular body, and an outwardly extending flange 190 at the rearwardend of the two cooperating nose-jaws, and urges the nose-jaws rearwardlyinto the tubular body 184 by which the jaws are so constrained thattheir forward ends are closed together.

Forward movement of the nose-jaws relative to the tubular body, as whenthe pulling jaws advance a column of rivets into abutment with thenose-jaws (as explained with reference to FIG. 6), allows the nose-jawsto move radially outwardly and thus to open and allow the leading rivetof the column to pass between the nose-jaws. Thereafter the compressionspring 186 urges the nose-jaws rearwardly into the tubular body so thatthey close behind the leading rivet and the abutment surfaces 22, 24 ofthe nose-jaws abut the rearward end of the rivet head.

As will have been appreciated from the previous description, the mandrel12, has its head 16 above or forwardly of the nose-jaws and the mandrelstem 14 extends rearwardly between the nose-jaws, through the verticaltube 180, between the fingers of the two pulling jaws and, in thecondition of the machine shown in FIG. 7, its rear end is disposedforwardly of the rivet locating jaws 38, 40.

The rivet locating jaws 38, 40 are slidably mounted for lengthwisemovement along the upper surface of the rail 70 on opposite sides of thejet 42. The jet 42 is in the form ofa vertical bore, opening at theupper surface of the rail 70 and is axially aligned with the mandrelstem.

The locating jaws 38, 40 are each attached to one of the guide pins 168,170 respectively so that they open and close in conert with the openingand closing movements of the pulling jaws. The rivet locating jawsdefine, when closed, a cavity 192 which is shaped to accommodate a fedrivet and to hold the rivet with its head lower most and its shankextending upwardly in alignment with the mandrel. The cavity defined bythe closed locating jaws has an opening through which a rivet fed by thelocating plunger 58 can enter the cavlty.

The rivet locating plunger 58 is disposed within a guide channel 192which extends horizontally and at right angles to the rail 70 betweenthe lower end of the flight 76 and the cavity 192 between the locatingjaws.

The rivet locating plunger 58 is reciprocable lengthwise of the guidechannel by means of a double acting pneumatic piston-cylinderarrangement 198.

Admission of compressed air into the right hand end of the pneumaticcylinder 198 (as viewed in FIG. 8) moves the locating plunger to theleft, allowing the lowermost rivet in the flight to enter the guidechannel. Subsequent admission of air to the left hand end of thepneumatic cylinder 198 moves the locating plunger to the right, pushingthe rivet along the guide channel into position in the cavity 192 wherethe head of rivet overlies the opening of the jet 42.

The lower end of the vertical bore which forms the jet 42 is closed andintercepted by an air passage 200 which is connected by conduit (notshown) to the air supply. The bore of the jet 42 is also intercepted bythe detent 30. As can be seen in FIG. 8, the detent spring 34 iscompressed in a bore 202 by means of a retaining screw 204 and urges thedetent ball 32 transversely into the bore of jet 42 where it abutsagainst a stop 206 which prevents the ball falling out of the bore 202and down the bore of the jet 42.

The latch 44 comprises a vertical bar 208 which is pivotally mounted atits lower end on a pin 210 supported by the rail 70. A blade member 212is secured to the bar by a screw 214 and provides, at the upper end ofthe vertical bar, a blade 216 which extends horizontally towards themandrel stem. The blade member 212 is adjustable on the bar 208 to allowthe blade 216 to be adjusted lengthwise of the mandrel. A leaf spring218, which is secured to the rail by the retaining screw 204,resiliently urges the latch to pivot about the pin 210 so that the bladenormally engages the mandrel stem.

The pneumatic circuit for controlling the operation of the rivetingmachine will now be described with particular reference to FIG. 11.

The operation of the machine is primarily subject to the operation by amachine operator of a pedaloperated spring-return impulse valve 220. Thevalve 220 is connected to a source of air under pressure at 222.

When the machine operator depresses the pedal of valve 220 the airsupply 222 is connected through the valve to a conduit 224, the valveallowing a pulse of compressed air to pass along the conduit. This pulseinitiates performance of a complete cycle of operations by the machineunder the logical control of the control circuit.

The pulse is delivered by the conduit 224 to a 4-way S-port double pilotvalve 226. The valve 226 has an inlet port 228 through which it isconnected to the main supply of compressed air. A conduit 230 connectsan outlet port of the valve 226 to the upper end of the cylinder of themain jack 84, and a conduit 232 connects another outlet port of thevalve 226 to the lower end of the cylinder of the jack 84.

In the normal condition of the valve 226, the inlet port 228 isconnected through the valve to the conduit 232 so that pressure ismaintained in the lower portion of the cylinder of the jack 84 and thepiston 88 is in the raised or forward position and the conduit 230 isconnected through the valve to a silencer and thence to exhaust so thatpressure in the upper end of the cylinder is substantially atmospheric.

When a pulse is delivered along the conduit 224, the conduit 232 isdisconnected from the inlet port 228 and is connected to a conduit 234to exhaust at a jet 236. The jet 236 may be arranged to direct airissuing from the jet onto rivets descending the flight 76 in order toassist their passage along the flight. Simultaneously the conduit 230 isconnected through the valve 226 to the inlet 228 so that compressed airis delivered to the upper end of the cylinder of jack 84 and causes thepiston to descend through the cylinder lowering the piston rod andmoving the pulling jaws rearwardly. Descent of the piston in thecylinder of jack 84 sweeps air from the lower end of the cylinderthrough the conduit 232 via the valve 226 and the conduit 234 to exhaustthrough the jet 236.

As the pulling jaws descend, they mechanically actuate and hold actuateda 4-way, 5-port pilot return trip valve 238.

In the normal condition of the valve 238, the main air supply isconnected via an inlet port 240 through the valve 238 and a conduit 232to one end of the cylinder of the piston cylinder arrangement 198 (theleft hand end as viewed in FIG. 8) so that the rivet locating plunger 58is moved to the right (as shown in FIGS. 5, 6 and 8) thereby advancing arivet along the guide channel into the cavity between the locating jaws.

When the valve 238 is actuated by the rearward movement of the pullingjaws, the left hand end of the cylinder 198 is connected via the conduit242 via the valve 238 to exhaust, and the air supply via port 240 isconnected through the valve and a conduit 244 to the right hand end ofthe cylinder 198 moving the piston therein to withdraw the rivetlocating plunger 58 along the guide channel 194 so as to admit a rivetfrom the flight into the guide channel.

Simultaneously with the delivery of air along conduit 244, air isdelivered from the conduit 244 through a branch conduit 246 to actuate a3-way, 3-port sprung return pilot valve 248. conduit 250 which leads tothe air jet 42 is normally connected through the valve 248 to exhaustbut when air is supplied along the conduit 246 to the valve 248 theconduit 250 is connected through the valve 248 to the main air supplyvia inlet port 252 so that air is delivered via the jet 42 to advance arivet forwardly along the mandrel when the rivet locating plungerwithdraws to admit a further rivet into the guide channel.

Once the valve 238 has been actuated by the rearwardly moving pullingjaws, it remains in the actuated condition while the pulling jawscomplete their rearward movement and begin to move forwardly again. Whenthe forwardly moving pulling jaws pass the position at which theypreviously actuated the trip valve, they disengage from the trip valveallowing it to return to its normal condition under the influence of thepressure of the main air supply delivered via a pilot conduit 254.

Similarly, a pilot conduit 256 connects the conduit 230, via anadjustable pressure regulator 258, to the valve 258, whereby the valve226 is returned to its normal condition due to an increase of airpressure in the conduit which occurs when the piston of jack 84 reachesthe end of its rearward movement. The pressure regulator is adjusted toprovide a short delay before returning the valve 226 to its normalcondition after the piston of jack 84 reaches the end of its rearwardstroke.

An air bleed 260 is provided to enable the pressure in conduit 224 toequalize with the atmosphere after delivery of each pulse along theconduit 224.

We claim:

1. Blind riveting apparatus, comprising abutment means for supporting arivet in a rivet setting operation,

an elongated mandrel having an enlarged head and a stem extendingrearwardly of the head, the mandrel being movable lengthwise of its axisrelative to the abutment means to pull the enlarged head through atubular rivet supported by the abutment means,

first and second holding means each of which may be in or out ofengagement with the mandrel and each of which is arranged to hold themandrel at a time when the other of the holding means is out ofengagement with the mandrel,

the first holding means being reciprocable in the axial direction of themandrel between a forward and a rearward location, and movable in adirection transverse to the mandrel axis between a mandrelholdingposition and a position remote from the mandrel and through a rivetfeeding position between said mandrel-holding position and said remoteposition, the first holding means being operable to hold and to move themandrel lengthwise of its axis while moving between the said forwardlocation and an intermediate location between the forward location andthe rearward location. and, in the rivet feeding position, to engage arivet on the mandrel stem while moving independently of the mandrelbetween the said intermediate location and the rearward location, and,in the remote position at the rearward location to allow a rivet to movealong the mandrel past the first holding means,

means being provided for advancing forwardly along the mandrel from therearward end thereof and past the first holding means,

2. Blind riveting apparatus according to claim 1, wherein the firstholding means comprises a pair of pulling jaws.

3. Blind riveting apparatus according to claim 2, wherein each pullingjaw is associated with a cam which constrains the jaw to move betweenthe mandrel holding position and the said position remote from themandrel.

4. Blind riveting apparatus according to claim 3, wherein each pullingjaw is spring biassed to move transversely towards the position remotefrom the mandrel and is constrained to move in opposition to the springbias by the associated cam.

5. Blind riveting apparatus according to claim 1, wherein the secondholding means is disposed rearwardly of the first holding means.

6. Blind riveting apparatus according to claim 1, wherein the secondholding means comprises a detent positioned to engage the mandrel onlywhen the mandrel is at or near its rearward position.

7. Blind riveting apparatus according to claim 1, wherein the means foradvancing rivets forwardly from the rear end of the mandrel and past thefirst holding means comprises jet means for directing a jet of gasforwardly along the mandrel.

8. Blind riveting apparatus according to claim 7, wherein the jet meansis disposed'rearwardly of the rear end of the mandrel when the mandrelis in its rearward position.

9. Blind riveting apparatus according to claim 1, including means fordelivering tubular rivets to and aligning the rivets with the mandrel ina position through which the stem of the mandrel extends when themandrel is in a rearward position and which is rearwardly of the mandrelwhen the mandrel is in a forward position.

10. Blind riveting apparatus according to claim 9, wherein the means fordelivering and aligning the tubular rivets is arranged to deliver therivets to and align them at a position which is forwardly of the secondholding means and the means for advancing rivets forwardly from the rearend of the mandrel.

11. Blind riveting apparatus according to claim 10, wherein the meansfor delivering and aligning rivets comprises a pair of locating jawsarranged to open and close in timed relationship to the movements of themandrel for holding a rivet in alignment with the mandrel, and means forfeeding rivets one at a time into position between the locating jaws.

12. Blind riveting apparatus according to claim 1, wherein the abutmentmeans comprises cooperating abutment jaws adapted to be opened by arivet moving forwardly along the mandrel and to resist rearward movementof a rivet positioned forwardly of the abutment jaws.

13. Blind riveting apparatus according to claim 1, including a latch forsupporting a column of rivets on the mandrel at a position forwardly ofthe first holding means and rearwardly of the abutment means, the latchbeing adapted to permit rivets to move forwardly along the mandrel pastthe latch and to prevent rivets moving rearwardly past the latch.

14. Blind riveting apparatus comprising, an elongate mandrel having astern and an enlarged head, the stem extending rearwardly of the head,

abutment means arranged to form an abutment peripherally of the mandrelgripping jaws disposed rearwardly of the abutment means, the grippingjaws being movable between an open position and a closed positioninwhich the jaws grip the stem of the mandrel, the gripping jaws alsobeing reciprocable in a direction lengthwise of the mandrel whilegripping the mandrel so as to reciprocate the mandrel between a forwardposition and a rearward position relative to the abutment means,

holding means disposed rearwardly of the gripping jaws at a positionwhich is rearwardly of the mandrel when the mandrel is in said forwardposition, said holding means being arranged to hold the mandrel when themandrel is at its rearward position, means for locating a rivet at alocation which is forwardly of the holding means and rearwardly of themandrel when the mandrel is in said forward position and for aligningsaid rivet with the stem of the mandrel,

and means for advancing said rivet forwardly from said location and pastthe gripping jaws when the gripping jaws are open.

15. Blind riveting apparatus according to claim 14, wherein the holdingmeans comprises a resilient detent.

16. Blind riveting apparatus according to claim 14 wherein the means foradvancing a rivet comprises jet means for directing a jet of gasforwardly along the mandrel.

17. Blind riveting apparatus, comprising abutment means for supporting arivet in a rivet setting operation,

an elongated mandrel having an enlarged head and a stem extendingrearwardly of the head, the mandrel being movable lengthwise of its axisrelative to the abutment means to pull the enlarged head through atubular rivet supported by the 30 abutment means,

first and second holding means each of which may be in or out ofengagement with the mandrel and each of which is arranged to hold themandrel at a time when the other of the holding means is out ofengagement with the mandrel,

the first holding means being reciprocable in the lengthwise directionof the mandrel between a rearward location and a forward location whichis rearwardly of the abutment means, and being movable in a directiontransverse to the mandrel axis between a mandrel-holding position and aposition remote from the mandrel and through a rivet feeding positionbetween said mandrel-holding position and said remote position, thefirst holding means being operable to hold and to move the mandrellengthwise of its axis while in the mandrel holding position and movingbetween the said forward location and an intermediate location betweenthe forward location and the rearward location, and to engage a rivet onthe mandrel stem while in the rivet feeding position and movingindependently of the mandrel between said intermediate location and therearward location, and to allow a rivet to move along the mandrel pastthe first holding means while in the remote position at the rearwardlocation,

the second holding means being disposed rearwardly of the said rearwardlocation'and of the first holding means,

and there being advancing means for advancing rivets forwardly along themandrel and past the first holding means from a position which isrearwardly of the mandrel when the mandrel is in a forward position.

18. Blind riveting apparatus according to claim 17, wherein theadvancing means comprises jet means for directing a jet of gas forwardlyalong the mandrel.

19. Blind riveting apparatus according to claim 17, wherein the secondholding means is disposed at a position which is spaced rearwardly ofthe mandrel when the mandrel is in a forward position.

20. Blind riveting apparatus according to claim 19, including means fordelivering rivets to and aligning the rivets with the mandrel at aposition which is forward of the second holding means and the advancingmeans and which is rearward of the mandrel when the mandrel is in aforward position.

21. Blind riveting apparatus according to claim 20, wherein the meansfor delivering and aligning rivets comprises locating jaws arranged toopen and close in timed relationship to the movements of the mandrel forholding a rivet in alignment with the mandrel, and means for feedingrivets one at a time into position between the locating jaws.

22. Blind riveting apparatus, comprising abutment means for supporting arivet during a rivet setting operation,

an elongated mandrel having an enlarged head and a stem extendingrearwardly of the head, the mandrel being movable lengthwise of its axisrelative to the abutment means to pull the enlarged head through a rivetsupported by the abutment means,

first and second holding means for holding the mandrel, the firstholding means being disposed rearwardly of the abutment means andreciprocable in a direction lengthwise of the mandrel to hold and movethe mandrel between a rearward position in which the mandrel is engagedand held by the second holding means and a forward position in which themandrel is disengaged from the second holding means,

and means for advancing a rivet forwardly along the mandrel from aposition which is forwardly of the second holding means and rearwardlyof the mandrel when the mandrel is in the forward position,

wherein the first holding means and the abutment means are operable toretract from the mandrel so as to allow a rivet to move forwardly alongthe mandrel past the first holding means and the abutment means.

23. Blind riveting apparatus according to claim 22 wherein the secondholding means comprises a springoperated detent which resilientlyengages the mandrel when the mandrel is at its rearward position.

24. Blind riveting apparatus according to claim 22 wherein the means foradvancing a rivet along the mandrel comprises means for directing a jetof gas forwardly along the mandrel.

25. Blind riveting apparatus according to claim 22, wherein the meansfor advancing a rivet along the mandrel comprises a jet for issuing astream of gas.

26. Blind riveting-apparatus according to claim 22 wherein the firstholding means comprises a pair of aws.

27. Blind riveting apparatus according to claim 26, including cam meansfor guiding the jaws of the first holding means to hold and to retractfrom the mandrel during movement of the jaws lengthwise of the mandrel.

28. Blind riveting apparatus according to claim 22,

wherein the abutment means comprises spring-loaded cooperating abutmentjaws adapted to be opened resiliently by a rivet moving forwardly alongthe mandrel and to resist rearward movement of a rivet which ispositioned forwardly of the abutment jaws.

29. Blind riveting apparatus according to claim 22, wherein latch meansis provided at a position forwardly of the first holding means andrearwardly of the abutment means, the latch means being adapted topermit movement of rivets forwardly along the mandrel past the latchmeans and to prevent movement of rivets rearwardly past the latch means.

30. Blind riveting apparatus according to claim 22 including means fordelivering tubular rivets to the said position, which is forwardly ofthe second holding means and rearwardly of the mandrel when the mandrelis in the forward position, and for aligning the rivets with the stem ofthe mandrel.

31. Blind riveting apparatus according to claim 30, wherein the meansfor delivering and aligning rivets comprises a pair of rivet locatingjaws disposed on opposite sides of the mandrel axis and arranged to openand close in timed relationship to the movements of the mandrel.

32. Blind riveting apparatus according to claim 22, wherein said rivetis advanced along a portion of said mandrel by said first holding means.

v mm STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,828,603Dated August 13, 1974 Inventor(s David John Sheffield et a1 It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:-

In Clairn 1, col umn 12, line 20, insert rivets after "advancing".

Q In Claim 17, co1un n'1 3, line delete "30".

Signet? 19th .day of November 1974.

(SEAL) Attest:

MCCOY M. GIBSON LJR. I c. MARSHALL DANN Attesting Officer 1 Commissionerof Patents Foanpo-wsouo-es) Q V YUSCOMWDC comb";

i ".5. GOVERNMENT PRINTING OFFICE "I! O-Qil-JSI

1. Blind riveting apparatus, comprising abutment means for supporting arivet in a rivet setting operation, an elongated mandrel having anenlarged head and a stem extending rearwardly of the head, the mandrelbeing movable lengthwise of its axis relative to the abutment means topull the enlarged head through a tubular rivet supported by the abutmentmeans, first and second holding means each of which may be in or out ofengagement with the mandrel and each of which is arranged to hold themandrel at a time when the other of the holding means is out ofengagement with the mandrel, the first holding means being reciprocablein the axial direction of the mandrel between a forward and a rearwardlocation, and movable in a direction transverse to the mandrel axisbetween a mandrel-holding position and a position remote from themandrel and through a rivet feeding position between saidmandrel-holding position and said remote position, the first holdingmeans being operable to hold and to move the mandrel lengthwise of itsaxis while moving between the said forward location and an intermediatelocation between the forward location and the rearward location, and, inthe rivet feeding position, to engage a rivet on the mandrel stem whilemoving independently of the mandrel between the said intermediatelocation and the rearward location, and, in the remote position at therearward location to allow a rivet to move along the mandrel past thefirst holding means, means being provided for advancing forwardly alongthe mandrel from the rearward end thereof and past the first holdingmeans,
 2. Blind riveting apparatus according to claim 1, wherein thefirst holding means comprises a pair of pulling jaws.
 3. Blind rivetingapparatus according to claim 2, wherein each pulling jaw is associatedwith a cam which constrains the jaw to move between the mandrel holdingposition and the said position remote from the mandrel.
 4. Blindriveting apparatus according to claim 3, wherein each pulling jaw isspring biassed to move transversely towards the position remote from themandrel and is constrained to move in opposition to the spring bias bythe associated cam.
 5. Blind riveting apparatus according to claim 1,wherein the second holdIng means is disposed rearwardly of the firstholding means.
 6. Blind riveting apparatus according to claim 1, whereinthe second holding means comprises a detent positioned to engage themandrel only when the mandrel is at or near its rearward position. 7.Blind riveting apparatus according to claim 1, wherein the means foradvancing rivets forwardly from the rear end of the mandrel and past thefirst holding means comprises jet means for directing a jet of gasforwardly along the mandrel.
 8. Blind riveting apparatus according toclaim 7, wherein the jet means is disposed rearwardly of the rear end ofthe mandrel when the mandrel is in its rearward position.
 9. Blindriveting apparatus according to claim 1, including means for deliveringtubular rivets to and aligning the rivets with the mandrel in a positionthrough which the stem of the mandrel extends when the mandrel is in arearward position and which is rearwardly of the mandrel when themandrel is in a forward position.
 10. Blind riveting apparatus accordingto claim 9, wherein the means for delivering and aligning the tubularrivets is arranged to deliver the rivets to and align them at a positionwhich is forwardly of the second holding means and the means foradvancing rivets forwardly from the rear end of the mandrel.
 11. Blindriveting apparatus according to claim 10, wherein the means fordelivering and aligning rivets comprises a pair of locating jawsarranged to open and close in timed relationship to the movements of themandrel for holding a rivet in alignment with the mandrel, and means forfeeding rivets one at a time into position between the locating jaws.12. Blind riveting apparatus according to claim 1, wherein the abutmentmeans comprises cooperating abutment jaws adapted to be opened by arivet moving forwardly along the mandrel and to resist rearward movementof a rivet positioned forwardly of the abutment jaws.
 13. Blind rivetingapparatus according to claim 1, including a latch for supporting acolumn of rivets on the mandrel at a position forwardly of the firstholding means and rearwardly of the abutment means, the latch beingadapted to permit rivets to move forwardly along the mandrel past thelatch and to prevent rivets moving rearwardly past the latch.
 14. Blindriveting apparatus comprising, an elongate mandrel having a stem and anenlarged head, the stem extending rearwardly of the head, abutment meansarranged to form an abutment peripherally of the mandrel gripping jawsdisposed rearwardly of the abutment means, the gripping jaws beingmovable between an open position and a closed position in which the jawsgrip the stem of the mandrel, the gripping jaws also being reciprocablein a direction lengthwise of the mandrel while gripping the mandrel soas to reciprocate the mandrel between a forward position and a rearwardposition relative to the abutment means, holding means disposedrearwardly of the gripping jaws at a position which is rearwardly of themandrel when the mandrel is in said forward position, said holding meansbeing arranged to hold the mandrel when the mandrel is at its rearwardposition, means for locating a rivet at a location which is forwardly ofthe holding means and rearwardly of the mandrel when the mandrel is insaid forward position and for aligning said rivet with the stem of themandrel, and means for advancing said rivet forwardly from said locationand past the gripping jaws when the gripping jaws are open.
 15. Blindriveting apparatus according to claim 14, wherein the holding meanscomprises a resilient detent.
 16. Blind riveting apparatus according toclaim 14 wherein the means for advancing a rivet comprises jet means fordirecting a jet of gas forwardly along the mandrel.
 17. Blind rivetingapparatus, comprising abutment means for supporting a rivet in a rivetsetting operation, an elongated mandrel having an enlarged head and astem extending rearwardly of the head, the mandrel being movAblelengthwise of its axis relative to the abutment means to pull theenlarged head through a tubular rivet supported by the 30 abutmentmeans, first and second holding means each of which may be in or out ofengagement with the mandrel and each of which is arranged to hold themandrel at a time when the other of the holding means is out ofengagement with the mandrel, the first holding means being reciprocablein the lengthwise direction of the mandrel between a rearward locationand a forward location which is rearwardly of the abutment means, andbeing movable in a direction transverse to the mandrel axis between amandrel-holding position and a position remote from the mandrel andthrough a rivet feeding position between said mandrel-holding positionand said remote position, the first holding means being operable to holdand to move the mandrel lengthwise of its axis while in the mandrelholding position and moving between the said forward location and anintermediate location between the forward location and the rearwardlocation, and to engage a rivet on the mandrel stem while in the rivetfeeding position and moving independently of the mandrel between saidintermediate location and the rearward location, and to allow a rivet tomove along the mandrel past the first holding means while in the remoteposition at the rearward location, the second holding means beingdisposed rearwardly of the said rearward location and of the firstholding means, and there being advancing means for advancing rivetsforwardly along the mandrel and past the first holding means from aposition which is rearwardly of the mandrel when the mandrel is in aforward position.
 18. Blind riveting apparatus according to claim 17,wherein the advancing means comprises jet means for directing a jet ofgas forwardly along the mandrel.
 19. Blind riveting apparatus accordingto claim 17, wherein the second holding means is disposed at a positionwhich is spaced rearwardly of the mandrel when the mandrel is in aforward position.
 20. Blind riveting apparatus according to claim 19,including means for delivering rivets to and aligning the rivets withthe mandrel at a position which is forward of the second holding meansand the advancing means and which is rearward of the mandrel when themandrel is in a forward position.
 21. Blind riveting apparatus accordingto claim 20, wherein the means for delivering and aligning rivetscomprises locating jaws arranged to open and close in timed relationshipto the movements of the mandrel for holding a rivet in alignment withthe mandrel, and means for feeding rivets one at a time into positionbetween the locating jaws.
 22. Blind riveting apparatus, comprisingabutment means for supporting a rivet during a rivet setting operation,an elongated mandrel having an enlarged head and a stem extendingrearwardly of the head, the mandrel being movable lengthwise of its axisrelative to the abutment means to pull the enlarged head through a rivetsupported by the abutment means, first and second holding means forholding the mandrel, the first holding means being disposed rearwardlyof the abutment means and reciprocable in a direction lengthwise of themandrel to hold and move the mandrel between a rearward position inwhich the mandrel is engaged and held by the second holding means and aforward position in which the mandrel is disengaged from the secondholding means, and means for advancing a rivet forwardly along themandrel from a position which is forwardly of the second holding meansand rearwardly of the mandrel when the mandrel is in the forwardposition, wherein the first holding means and the abutment means areoperable to retract from the mandrel so as to allow a rivet to moveforwardly along the mandrel past the first holding means and theabutment means.
 23. Blind riveting apparatus according to claim 22wherein the second holding means comprises a spring-operated detentwhich resiliently engages tHe mandrel when the mandrel is at itsrearward position.
 24. Blind riveting apparatus according to claim 22wherein the means for advancing a rivet along the mandrel comprisesmeans for directing a jet of gas forwardly along the mandrel.
 25. Blindriveting apparatus according to claim 22, wherein the means foradvancing a rivet along the mandrel comprises a jet for issuing a streamof gas.
 26. Blind riveting apparatus according to claim 22 wherein thefirst holding means comprises a pair of jaws.
 27. Blind rivetingapparatus according to claim 26, including cam means for guiding thejaws of the first holding means to hold and to retract from the mandrelduring movement of the jaws lengthwise of the mandrel.
 28. Blindriveting apparatus according to claim 22, wherein the abutment meanscomprises spring-loaded cooperating abutment jaws adapted to be openedresiliently by a rivet moving forwardly along the mandrel and to resistrearward movement of a rivet which is positioned forwardly of theabutment jaws.
 29. Blind riveting apparatus according to claim 22,wherein latch means is provided at a position forwardly of the firstholding means and rearwardly of the abutment means, the latch meansbeing adapted to permit movement of rivets forwardly along the mandrelpast the latch means and to prevent movement of rivets rearwardly pastthe latch means.
 30. Blind riveting apparatus according to claim 22including means for delivering tubular rivets to the said position whichis forwardly of the second holding means and rearwardly of the mandrelwhen the mandrel is in the forward position, and for aligning the rivetswith the stem of the mandrel.
 31. Blind riveting apparatus according toclaim 30, wherein the means for delivering and aligning rivets comprisesa pair of rivet locating jaws disposed on opposite sides of the mandrelaxis and arranged to open and close in timed relationship to themovements of the mandrel.
 32. Blind riveting apparatus according toclaim 22, wherein said rivet is advanced along a portion of said mandrelby said first holding means.